نوع مقاله : مقاله پژوهشی

نویسندگان

• حسن اوجاقلو ¹
• زهرا امیری ²
• سپیده ارومی ³

¹ استادیار، گروه علوم و مهندسی آب، دانشکده کشاورزی، دانشگاه زنجان، زنجان، ایران

² دانشجوی کارشناسی ارشد، گروه علوم و مهندسی آب، دانشگاه زنجان، زنجان، ایران.

³ دانشجوی کارشناسی، گروه علوم و مهندسی آب، دانشگاه زنجان، زنجان، ایران.

چکیده

ارتقای بهره‌وری مصرف آب کشاورزی  یکی از راهکارهای به‌زراعی مهم برای رسیدن به کشاورزی پایدار محسوب ‌می‌شود. در این راستا، مکان‌یابی زمین­های دیم مناسب به‌منظور اجرای آبیاری تکمیلی از اقداماتی است که برای بهبود بهره‌وری مصرف آب و امنیت غذایی مورد توجه محققان قرار گرفته است. در این پژوهش، با استفاده از روش تصمیم‌گیری تحلیل سلسله ‌مراتبی (AHP) زمین­های دیم مستعد آبیاری تکمیلی در استان زنجان تعیین شد. برای این منظور، معیارهای دسترسی به منابع آب، کیفیت آب، ویژگی­ های کمی و کیفی خاک، اقلیم، راه دسترسی و توپوگرافی در نظر گرفته شد. مقایسه ­های زوجی بین معیارها و طبقه‌بندی زمین­ ها با استفاده از نقشه‌های پهنه‌بندی تهیه شده در محیط ArcGIS اجرا و نشان داده شد که بیشترین وزن و اهمیت را معیار دسترسی به منابع آب و کمترین وزن را معیارهای جاده دسترسی و توپوگرافی داراست. بر اساس نقشه‌های مکان‌یابی تهیه شده و انطباق آن با نقشۀ زمین­های دیم استان زنجان، کلاس زمین­های دیم از نظر قابلیت اجرای آبیاری تکمیلی شامل 19 درصد کاملاً مناسب، 40/6 درصد مناسب، 27/8 درصد با محدودیت متوسط، 10/6 درصد نامناسب و 2 درصد کاملاً نامناسب شناخته شد.

کلیدواژه‌ها

• آبیاری تکمیلی
• به زراعی
• اراضی دیم
• نقشه پهنه بندی

موضوعات

• مدیریت شبکه های آبیاری

عنوان مقاله [English]

Locating Suitable Rainfed Land for Supplemental Irrigation to Improve Water Productivity

نویسندگان [English]

• Hassan Ojaghlou ¹
• Zahra Amiri Abdobochali ²
• Sepideh Oroumi ³

¹ Assistant Professor, Department of Water Science and Engineering, Faculty of Agriculture, University of Zanjan, Zanjan, Iran

² M.Sc, Department of Water Science and Engineering, Faculty of Agriculture, University of Zanjan, Zanjan, Iran

³ B.Sc, Department of Water Science and Engineering, Faculty of Agriculture, University of Zanjan, Zanjan, Iran

چکیده [English]

Extended Abstract
Introduction
Population pressures continue to undermine effective land and water management in many developing countries. Improving water productivity in agricultural lands is essential for enhancing production and adapting to the water scarcity crisis. Rainfed lands play a crucial role in food production. Breeding and crop improvement are two important strategies for increasing water productivity. Supplemental irrigation is considered one of the crop improvement managements in rainfed lands. This management approach involves providing one or two irrigations during critical growth periods, which can significantly improve yield and water productivity on rainfed lands. However, the effectiveness of supplemental irrigation depends on accessibility to water resources, water quality, soil fertility, and other important factors. Therefore, locating suitable rainfed areas for implementing supplemental irrigation will be the first step. The area under cultivation of rainfed lands in Zanjan Province is substantial, covering 338,000 ha. It is recognized as one of the provinces with a high capacity for producing rainfed crops in the country. This paper presents a comparative analysis of the Analytic Hierarchy Process (AHP) in the context of decision-making for supplemental irrigation site selection using Geographic Information Systems (GIS) in Zanjan Province. For this purpose, several criteria were employed in the selection process, based on the literature concerning factors that influence supplementary irrigation performance.
 Methodology
In this research, Zanjan Province was selected as the study area. The criteria examined in this research encompass the accessibility of water resources, water quality, soil properties, climatic factors, topography, and road accessibility, including its sub-criteria. The AHP method was employed to prioritize rainfed lands for supplemental irrigation. The AHP process consists of three key components: identifying a hierarchy of objectives, criteria and alternatives; conducting pairwise comparisons of the criteria; and integrating the results from these comparisons to determine the relative importance across all levels of the hierarchy. The factors influencing site selection exhibit various characteristics; some are descriptive and can vary in quantity, while others possess numerical values. Consequently, it is essential to standardize the values and weights of each factor. Zoning maps for each sub-criterion were prepared as information layers using ArcGIS software, and subsequently, all prepared maps were re-scored through a reclassification process. The pairwise comparison tables for the AHP method were generated using the extAHP plugin in ArcGIS software, establishing the weight coefficients for the criteria. The land classification map was created by overlaying the zoning maps corresponding to each criterion while considering the assigned weights. Finally, by integrating the obtained map with the rainfed land map of Zanjan Province, suitable rainfed fields for supplementary irrigation were determined.
 Results and Discussion
There are generally no significant restrictions in most areas of Zanjan Province regarding the water quality, soil properties, climatic factors, road accessibility, and topography for implementing supplemental irrigation. However, in certain regions, limited accessibility to water resources has caused restrictions. The access to water resources received the highest weight and importance in the AHP prioritization method, while the water quality criterion ranked second in significance and influence on decision-making. Based on classified land maps of Zanjan Province, the central and eastern regions received higher scores for implementing supplemental irrigation. Additionally, the central areas of rain-fed lands were identified as having a high potential for supplemental irrigation capability. The area and percentage of various land classes were calculated. Approximately 44.2% of the province's land is classified as either completely suitable or suitable for supplemental irrigation, while about 32.4% falls within the moderate range, and 23.4% is deemed unsuitable. Furthermore, around 59.6% of rainfed land is classified as suitable or completely suitable, about 27.8% falls within the moderate range, and 12.6% is considered unsuitable.
 Conclusions
Improving yield and water productivity through supplemental irrigation in rainfed areas is a crucial crop improvement strategy. Zanjan Province, with its significant area of rainfed land, relatively favorable rainfall, and good soil quality in most regions, possesses significant production and productivity potential in these agricultural areas. In this research, suitable rainfed areas in Zanjan Province were identified for supplemental irrigation by considering relevant criteria and utilizing the AHP method. Approximately 59.6.2% of the areas in the Zanjan Province, particularly in the central and eastern regions of Zanjan, were identified as suitable or fully suitable for supplemental irrigation, while the remaining lands faced low to severe limitations. Ultimately, the effectiveness of the AHP method can be assessed in feasibility studies for the implementation of viable water projects, and its use is recommended during the initial project identification phase. The final selection of suitable locations for implementing supplemental irrigation is suggested by integrating the results obtained from AHP with findings from field surveys and regional conditions. It is indicated that the water resources required for implementing supplemental irrigation can be harvested from the current permitted allocations, without any new extraction of water resources.
 

کلیدواژه‌ها [English]

• Supplemental irrigation
• Crop improvement
• Rainfed land
• Zoning map